


Mack The Knife

by TheKnightsWhoSay



Category: Shingeki no Kyojin | Attack on Titan
Genre: AU, Crossover, Cyberpunk AU, Enemies to Lovers, Eventual Smut, F/F, F/M, Gangwar AU, M/M, Polyamory, Society is a lot more chill about sex and polyamory and intimacy, cyberassassin!Levi, gangleader!Erwin, ripperdoc!Hange
Language: English
Status: In-Progress
Published: 2021-02-14
Updated: 2021-02-26
Packaged: 2021-03-15 07:41:41
Rating: Mature
Warnings: Graphic Depictions Of Violence
Chapters: 2
Words: 6,203
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29432601
Author URL: https://archiveofourown.org/users/TheKnightsWhoSay/pseuds/TheKnightsWhoSay
Summary: As his goggles adjust to the darkness within, Erwin can only stare in shock. Nanaba had been right: there is no bomb. Erwin stares at the curled-up bundle in the corner, scans confirming his suspicions.Militech’s latest secret weapon is not a bomb. It’s a person.[A Cyberpunk Gangwar AU]
Relationships: Levi Ackerman/Erwin Smith, Mike zacharias & erwin smith & nanaba, Moblit Berner/Hange Zoë, Nanaba/Mike Zacharias
Comments: 18
Kudos: 61





	1. Chapter 1

**Author's Note:**

> Song: [Mack The Knife ](https://www.youtube.com/watch?v=28ULUQgxJ5M&ab_channel=BryanGalvez) by Louis Armstrong
> 
> This story is inspired by this amazing artwork [[here ](https://moxie-sketches.tumblr.com/post/642592871052197888/consider-this-ex-corpo-erwin-and-street-kid-levi) & [here](https://moxie-sketches.tumblr.com/post/642701140748910592/reupload-since-i-wanted-to-make-some-adjustments) ] by [@moxie-sketches ](https://moxie-sketches.tumblr.com/)
> 
> This is a taste of a potential series/ longer story I would like to write, and I'm posting to see whether people would like to see more, and if so, what headcanons/ideas come to mind? There are lots of directions this crossover could go/ room for mini-arcs within the over-arching story I have planned, and I love help with brainstorming as I write, so please do let me know! <3

_Now, on the side-walk, ooh Sunday morning,_

_Lies a body just oozing life._

_And someone's sneaking round the corner_

_Could that someone be Mack the Knife?_

* * *

“Target sighted,” Nanaba’s voice sounds in their ears, “moving the Eagle into position.”

Mike and Erwin wait behind a huge pile of scrap, eyes fixed on the horizon. Sure enough, half a minute after Nanaba’s announcement, a convoy of heavy black vehicles appear on the deserted highway.

“Scanning the vehicles now,” says Nanaba through their comms.

The vans approach quickly, and Erwin scans the sky above them. He is pleased to re-affirm that their prized drone, ‘the Eagle’ is completely invisible to his scanners. It flies above the convoy, and he has faith that Nanaba will be able to figure out which one of the vehicles contains the weapon.

“Alright, team. I believe you want the third van. I repeat, the _third_ van.”

“You heard her,” says Erwin, “Everyone get ready to move. Nanaba, loop ‘em.”

“Yes boss,” she says.

Erwin fervently hopes that Militech never figures out this gaping flaw in their cyber-security. They’ve used this trick several times: hacking into and editing the optics of the convoy drivers so that they remain completely unaware that Erwin and his team are looting them as they drive. But that’s what you get for demanding all your employees upgrade their optics.

Nanaba gives them the all clear. A ten-minute timer flickers into life at the top edge of Erwin’s vision. Beneath them, the motorbike growls as Mike switches on the engine and they shoot out from behind the scrap heap, sun-baked dust whipping against their masks as they pick up speed.

Erwin keeps both arms around Mike’s waist as they pull up alongside the convoy until they reach the third vehicle, its heavily armoured side shining in the harsh sunlight.

“Nanaba, what’s the status on getting this thing open?” Erwin says into his comm, shielding his mouth from the wind.

“Uh…. Shit. I don’t think I can get through. Looks like some hefty manual locks I can’t hack into. I think we’ll have to go with plan B.”

“Alright. Let’s hope Moblit’s latest creation is as good as he says.”

Erwin unzips Mike’s backpack and takes out a spider-like bot about the size of a small cat. Four pairs of sensors glow red on the bot’s front face as Erwin switches it on and Mike brings the bike closer to the van so that there’s only a hand-width of space between them

Carefully, Erwin reaches out with both hands and places the bot on the side of the van, breathing a sigh of relief when the feet magnetically engage. He lets go, and it quickly scurries underneath the vehicle, disappearing from sight.

7 minutes to go.

They wait, wind hurtling against them as they keep pace with the convoy. It only takes Nanaba a minute to get the spider-bot inside but watching the clock count-down makes it seem like much longer. He pictures the bot cutting a small hole in the underbelly of the van, where the armour is thinnest, and scurrying inside.

“Ok, I’m in. Looks like I can get the bot to open the van doors from the inside. I’m just looking around, visual’s not the best. Hm, there’s an odd heat sig for some reason and I’m not detecting any radioactive material, what is-“ Nanaba curses colourfully in mandarin, “We have a problem.”

“What?” says Erwin.

“The weapon. It’s not a bomb.”

“It’s _not?_ Then what the fuck is it? _”_

5 minutes to go.

“I…I’m not sure.”

“Erwin,” Mike interrupts, “should we abort mission? We don’t have much time.”

“No, we’ve come too far. Maybe it’s a different kind of weapon. Continue with the plan. Oruo, Eld, get the hovercraft ready for weapon extraction.”

His team respond accordingly, and Erwin steels himself for the hard part. He pulls his knees up, holding on carefully to Mike’s shoulders. Once his feet are up, he moves into a crouch, ignoring the incredible speed of the ground moving below the wheels of the bike.

Before any doubts can creep into his mind, he stands, lets go of Mike, and launches himself upwards onto the top of the armoured van. The landing is heavy, knocking the air out of him whilst he scrabbles for purchase on the smooth metal, thankful for the magnetic gloves that help keep him there.

4 minutes to go.

He carefully shuffles on his belly along the roof of the van until he reaches the back and there’s a loud _clunk,_ audible even over the rush of wind, as the spider-bot opens the door from the inside. It swings open, and Erwin wastes no time swinging himself down and into the moving vehicle.

The intel had been good. The weapon had to be here. Militech’s latest, top-secret, highly experimental, ‘world-changing’ weapon, that’s what the audio files had said. The weapon was supposed to be small and incredibly deadly. Naturally, they had assumed it was fissile material: some new kind of nuclear bomb, definitely something worth stealing.

But as his goggles adjust to the darkness within, Erwin can only stare in shock.

Nanaba had been right: there is no bomb. Erwin stares at the curled-up bundle in the corner, scans confirming his suspicions.

Militech’s latest secret weapon is not a bomb. It’s a _person_.

* * *

They try not to stare. They all fail.

Hange, Moblit, Mike, Nanaba and Erwin all crowd around the strange man strapped to Hange’s surgical chair.

He’s naked, hairless and most of his skin has been replaced with some kind of metal which shines, silver tinged with purple, in the harsh lights of Hange’s medical room. Swathes of his body seem organic: the sides of his torso, his armpits, his groin, his ears and his face. His head looks like that of an android, the strange metal covers his scalp, a straight line across his forehead and behind his ears marking the difference between alloy and human skin. He looks hardly older than an adolescent with slender features and a sharp jawline, although Hange’s initial scans estimate him to be at least twenty.

The scans have picked up more than just his age. His limbic and central nervous system are almost entirely cyber, and of a calibre unseen before by any of them. Beneath his skin is sub-dermal armour that could withstand a nuclear bomb. But there is more that even Hange can’t understand, especially the purpose of the strange metallic skin. Hange won’t stop prodding him, fascinated, and their eyes are aglow with excitement.

“Should we… wake him up?” Mike asks eventually.

“What if he tries to kill us?” says Nanaba.

“I’m with Nanaba,” says Moblit, “if this guy’s some kind of Militech soldier, he’s probably not going to be friendly…”

“I still need to run more tests!” says Hange, “Always easier when the subject is unconscious. This metallic substance…it’s like it’s part bio, part alloy, I’ve never seen such a creative way of splicing molecular DNA with artificial chemical compounds…”

“Yeah, but maybe he could tell us useful stuff if we wake him up,” says Mike.

Thus, the debate continues. They haven’t told the rest of the Freedom Fighters: only those in the room and those involved in the heist know what has happened.

Through it all, Erwin stares at the strange man lying before them, mind racing. The man will wake up eventually, whether they boost him awake with stims or not, and he tries to figure out a plan. Without a complete assessment by Hange, the Freedom Fighter’s resident ripperdoc and cybernetic expert, there’s no way of knowing what this man is capable of.

It’s no secret that Militech carries out experiments on soldiers to try and develop new cyberware, but this is the first time that Erwin has seen Hange stumped. Whatever Militech did to this man, it must have worked, otherwise, why had their intel described him as such a powerful weapon?

“Uh, guys…” Hange says, and the circular bickering ceases, “his vitals are changing. I think he’s waking up.”

A hush descends and they all stare at the man as slowly, his eyes flicker open. His irises are pale grey, the pupils purple. There’s a long, tense moment where no one says anything, all faces in the room watching as the man’s pupils dilate and contract, slowly coming into focus.

Suddenly, panic grips his features.

“Woahhh there, don’t freak out,“ Erwin says, gesturing for the others to back away, “we’re not Militech, we’re not going to hurt you,” he puts his hands up.

His words don’t seem to work because the man looks just as panicked and he shifts, eyes growing even wider as he realises his wrists are tied down to the reclining chair. The bonds rattle as he shakes them, and Erwin knows that the others are subtly drawing their weapons whilst backing away.

“It’s ok. We just restrained you because we don’t know you yet. But we’re not going to hurt you."

He doesn’t seem to hear Erwin, and his thrashing within the restraints increases. Erwin stays close and reaches out a hand, placing it on the man’s wrist. The thrashing stops. The stranger seems terrified.

“Look, I’m going to remove these, alright? To show you that I mean what I say.”

“Erwin, is that a good idea?” Mike asks, gun now raised.

Erwin shoots him a nod that says _trust me_ and is thankful when Mike doesn’t say any more. The click of the restraints opening seems incredibly loud, and they all hold their breath as Erwin bends to release the restraints at the man’s ankles. The whole time, the man’s eerie grey eyes stay fixed on Erwin, still wide with panic, but he remains still and let’s Erwin remove the restraints.

“See? We just want to talk,” Erwin says, but then the man’s gaze flickers across the room, where four guns are openly trained on him.

There’s a split second where a look of mistrust passes over the man’s features, his whole body seems to glow faintly, ripples of lilac shifting across the strange silver segments of his body.

He vanishes.

Erwin blinks.

“Did he just…disappear?” Mike asks, spinning around wildly.

“Oh my _God_ …” breathes Hange, excitement tinging their voice.

Then Erwin feels the sharp edge of a blade pressed against his throat.

Curses all around, as the others train their weapons on the small figure behind Erwin. He glances down and sees the strange silvery skin of the hand holding the blade at his neck.

“Show me the way out. Or I kill him,” says the man, voice rasping and raw like he hasn’t spoken in a long time.

The knife is pressed tight against his left carotid artery. Erwin doesn’t doubt his threat.

“Everyone, stand down. Do as he says.”

No one moves. The blade presses harder and Erwin feels the skin break, a trickle of his own blood leaking down into his shirt. Slowly, Nanaba lowers her gun and opens the door, “you’ll want to go up the stairs until you reach the red door at the top. Then it’s down the corridor, exit third door on your right.”

“Move,” growls the man behind Erwin, “slowly. One wrong step and you’re dead, got it?”

“Understood,” Erwin replies, heartbeat loud in his ears. A familiar calm settles over him, the feeling of his Life hanging in the balance.

“I’ll have my gun trained on him the whole time,” Mike says to Erwin, but he can hear the underlying worry in his voice.

Together, Erwin and the stranger inch towards the door. It’s an odd dance. They have to move together due to the stranger’s short stature and insistence on keeping the blade pressure steady. They finally shuffle all the way to the base of the stairs, the stranger walking them backwards so that he can keep his eyes on the others.

They inch up the stairs, the stranger’s grip on Erwin’s torso tight, fingers biting into his sides. If Mike were to shoot now, it would be hard not to hit Erwin. His senses narrow to the sharp edge pressed so close to his artery, where he can feel and hear his blood rushing.

It seems to take a lifetime for them to climb the stairs, and Erwin’s enhanced hearing picks up the light crackle of Hange calling for reinforcements from the room below.

“If anyone else shows up, I kill him,” the stranger says.

 _Fuck,_ Erwin thinks. _Of course, he’s got crazy hearing too. On top of being able to turn fucking invisible._

They finally stumble through the red door at the top of the stairs, the hinges whining as it swings open. Nanaba hadn’t lied, the exit really is the third door on the left, and Erwin holds his breath as they reach it with Mike, Nanaba and Moblit right behind them, weapons still raised.

The glare of the streetlight outside is startling as a cold wind hits them, but the stranger’s grip doesn’t let up. Finally, he and Erwin stand, pressed close in their deadly embrace and facing the others, the deserted street behind them.

“We’re out now, so let me go,” Erwin says.

“As soon as I let you go, what’s to stop them shooting me?”

“I told you, we don’t want to hurt you.”

“I don’t believe you.”

He hardly feels it as the blade slices through his skin. It’s only when Erwin chokes on the blood spilling from his body, that he realises what has happened. He crumples to the floor, hands clutching desperately at his neck.


	2. Chapter 2

**Summary for the Chapter:**

> "How do we catch an invisible guy who doesn’t want to be caught, without alerting Militech that we’re looking for him?"

**Notes for the Chapter:**

> I am personally a fan of the 'everyone's super chill about gender/sexuality/polyamory/physical intimacy in the future' (a la Jack Harkness).
> 
> I have also taken the artistic liberty to diversify our cast. Night City is a pretty diverse place, after all.

The World swims slowly into colour as Erwin blinks awake. He tries to sit upright, but hands push him down just as he becomes aware of how much his body aches.

“Woahhh there, don’t you dare try and move just yet,” says Hange.

“How long was I out?” His throat is dry, and his voice sounds faint.

“37 hours and 23 minutes,” they reply, quick as a beat, “got you patched up pretty quickly, and the healing accelerants worked their usual wonders, but healing’s easier done whilst unconscious.”

“What have I missed?”

Hange sighs and shakes their head, “Only you would wake form a near-death experience and be right back to work. I’ll call the others: they can fill you in. But I don’t want you leaving base for at least another 24 hours, you hear me? And nothing strenuous for a week, you still gotta heal.”

“Thanks, Hange, you’re a legend.”

“Yeah, I fucking am, although it sure is lucky that our runaway missed your carotid artery when he, y’know, slashed your throat,” they say, drawing a finger across their neck. Years working as a Trauma Team medic have given Hange a distinctive black humour, but Erwin’s always loved that about them. He gets it.

“He did? How interesting…” Erwin says, mind already trying to put together the pieces.

Mike and Nanaba show up five minutes later and relief is clear on both faces, “Erwin, you’re awake, thank fuck,” says Mike. They both look tired: Nanaba’s eyes are red as they usually are when she’s been netrunning too long without sleep. Mike’s treasured corkscrew coils lack their usual shine, frizzy as if he’s been running his hand through the strands too often from stress.

“Yeah, I’m awake,” says Erwin, “what’s the update?”

Mike sits down heavily on the stool beside Erwin’s reclining chair. Nanaba paces, eyes glowing blue as she continues to run programs through her optics.

“Well,” begins Mike, “Mr. Invisible disappeared on us, quite literally, as soon as he…well. Tried to zero you. Anyway, I tried to chase him but…yeah. Turns out it’s a bit of bitch chasing an invisible guy? Anyway, I was needed to help Nanaba and Moblit get you down to Hange’s as soon as we could. You were losing blood pretty quickly.”

“Whilst Hange got to work, we called in Oruo and Eld,” says Nanaba, tucking a strand of blue hair behind her ear, “and this idiot here wanted to hand out detailed descriptions to everyone we knew and comb the city for the runaway.”

“Hey, it would be faster,” says Mike.

“Yeah, and would’ve been like a bright red bullseye for Militech. ‘Hi there, we’re the ones that stole your weapon and he’s here in Night City’, no way could we do that.”

“Good thinking, Nanaba,” says Erwin and Nanaba shoots Mike a victorious smirk, “so, has any course of action been decided so far?”

Nanaba tilts her head, “not really. I’ve been scanning a range of feeds across the city, and I’ve set up flags for any strange incidents but…It’s hard to set up alerts without being too specific and I’ve only got one set of eyes. Besides, you know how it is. There’s a _lot_ of weird shit happening in Night City, I can hardly scan it all. Mike, Oruo and Eld have been combing Freedom Fighter territory looking for signs but turns out that’s also pretty difficult without handing out descriptions of who we’re looking for.”

“I see. It’s a tricky one,” says Erwin, bushy eyebrows falling into his usual pensive frown.

“You can say that again,” says Mike, “we were hoping you would have some better ideas. How do we catch an invisible guy who doesn’t want to be caught, without alerting Militech that we’re looking for him?”

Hange snorts. The others turn to look at them, “What?” they say, “It’s a pretty crazy situation. Kind of funny, if you think about it.”

Erwin sighs, and he can feel the beginnings of a headache.

“Alright, first things that come to mind: Nanaba, is there anyone you can trust to help you search? How about that Armin kid, you keep saying he’s getting real good at netrunning.”

“Yeah, he’s good. And I’m pretty confident we can trust him. I’ll just have to make triple sure he doesn’t say anything to the two idiots he’s always hanging out with.”

“Great. Hange, have you found out anything more about our mysterious runaway from those scans you took?”

Hange thrums with excitement, “Shit is _fascinating_. I’ve never seen anything quite like it, especially that weird silver skin he’s got going. Did you know they wove a whole layer of iridophores between his skin and the sub dermal armour? Actual fucking guanine crystals!”

Three blank expressions stare back at them, “Oh,” Hange rolls their eyes, “basically, he’s got the same shit chameleon’s have in their skin to camouflage themselves. He’s probably not strictly-speaking turning completely invisible, just deflecting light and tricking our optics.”

“Ok, that’s something, so we know a little more. Did you find out anything that could help us track him down?”

“Uhhhh, I’m not sure. There’s plenty I still don’t understand…”

“Ok, well get Moblit to have a look with you. I know you do your best work when you have someone to bounce your ideas off.”

Hange nods.

“And finally,” says Erwin, “I have some questions for our source. They must have known the true nature of this weapon, and if so, they might have more answers for us than Hange’s scans can reveal. Besides, they need to explain why the fuck they didn’t tell us everything before we undertook that heist.”

“But only after another 24 hours of rest,” Hange warns, “don’t make me forcibly knock you out.”

A hint of a smile tugs at Erwin’s lips, “ _Si, Capo_ ,” he says with a mock salute. And then they all disperse, ready to get to work.

* * *

Most of the Freedom Fighters have long since gone to bed when the doors to Erwin’s office slide open. It isn’t much of an office, just a small room with a desk and his computer, but it’s useful when he needs to be alone to think and strategise.

He can tell it’s Mike without looking up from the gentle sound of his cyber joints whirring. Mike has more chrome than any of them, but he self-consciously keeps the seams of his non-organic implants well hidden under long-sleeved shirts.

“Why am I not surprised to see that you’re still up?” says Mike.

“Too much on my mind,” admits Erwin.

“That’s the default setting for you,” Mike says with a smile. As the smile fades, his shoulders drop, and concern flickers through his dark brown eyes, “how are you doing, E? I’d understand if you were feeling raw. Almost dying tends to do that to a guy.”

“I’ll be alright,” says Erwin, but his hand moves to the bandages around his neck and he feels the ghost of the blade slicing open his skin. He shivers. Mike moves around the desk, stepping close, and presses a reassuring hand to Erwin’s shoulder. Erwin moves his hand to cover Mike’s, his touch warm and familiar.

“You want company tonight? Bed’s big enough for three,” says Mike.

Erwin meets Mike’s gaze, “You know what, I think I do. I doubt I’ll get any sleep otherwise.”

After clearing up his desk and turning out the lights, Erwin follows Mike to the room Mike shares with Nanaba. It’s not the first time Erwin’s fallen into bed with them, enjoying the physical presence of trusted friends beside him as he sleeps; sometimes more than that, if they’re in the mood, but tonight is not one of those nights.

Nanaba is already asleep when the two men enter, and Erwin is suddenly aware of how exhausted he is, a deep ache pulsing throughout his body. He strips down to his boxers, yawning as he does. Mike changes into sweatpants, the dark skin of his back stark against the dull metal of his arms. He presses a chaste kiss to Erwin’s lips and pulls him into the bed after him.

They fall asleep like that, all three of them tangled together, and the steady breathing of the others lulls Erwin finally into sleep.

* * *

On his way in, Erwin nods to the girls in hot pink neon shorts guarding the entrance to Lizzie’s bar. They know him, of course. Everyone does.

It’s late in the morning and the last guests were kicked out hours ago. It’s always strange to see the place like this when the music is off, and most of the rooms empty. A few dancers lie half-asleep or smoking in the common areas.

Erwin navigates easily to the sound-proofed room hidden in the back. He finds it is already occupied by a man with light brown hair dressed in a smart suit, his eyes glowing white with the latest Militech optics.

“How was your trip out of town?” asks Nile.

“Successful,” replies Erwin. Nile doesn’t need to know more than that.

“Is that so? Then why have you called me here? I hardly need to remind you that every meeting is a risk.”

Erwin flashes a charming smile and fixes Nile with a direct stare. He gets right to the point, “Did you know what we would find?”

Nile can’t hold his gaze for long before he looks away, and the guilt is clear on his face.

“So, you did know?” Erwin infers. “Could’ve given us some warning.”

“I didn’t think it was important.”

“I think it was pretty important to know that we were after a _person_ and not a bomb.”

“I didn’t know for sure, I only suspected.”

“Well, now I want to hear all your suspicions, anything you’ve got.”

“Erwin, listen, this is…really dangerous territory. I’ve risked too much giving you what I have. You’ve got the weapon now, so just keep it away from Militech, ok? Lie low, stay quiet.”

“Are they looking for the weapon yet?”

“Of course, they are. But you did a good job, they can’t figure out where or when he was taking during the transport so there’s plenty of places they need to search.”

“Is there anything more you can tell us: where he came from, what was done to him, anything?”

Nile hesitates, concern flickering over his features.

“Nile, please. It’s gonna be hard enough to keep this secret when there’s so much we don’t know.”

Several minutes pass as Nile visibly debates with himself, but Erwin is good at this and he keeps his gaze fixed on the man, maintaining a reassuring expression.

“All I got was a name. The name of the project under which Militech was developing such ‘weapons’,” Nile says, voice low, “They call it Project Titan.”

Erwin nods, “Thank you, Nile.”

“Don’t contact me again,” is the reply he receives.

* * *

“Hange, there’s this great thing, did you know, it’s called _sleep_ ,” whines Moblit blearily as Hange drags him to their lab. His protests fall on deaf ears.

“So, I’ve been thinking about what Erwin said, about taking advantage of our runaway’s physiology to find a way to track him-“

“Hange. We were up ‘til 5am and I’ve only slept three hours. Can I at least get a coffee first?”

“What? Oh, yes. There’s coffee in my lab.”

“You can’t call that _piss_ , ‘coffee’. I’m swinging by the canteen.”

“Ughhhhhhhh, fine, _fine_ , but make it quick. So, as I was saying…” and Hange rattles away, Moblit’s brain still half-asleep and hardly prepared to keep up.

Hange’s arm remains clamped firmly around his own as they continue their rant, but Moblit doesn’t bother to disentangle them as he presses a mug under the dispenser in the canteen and the aroma of much-needed caffeine takes over his senses.

Across the room, Oruo and Mike watch the pair closely.

“What do you reckon? They fucking yet?” says Oruo, twirling his moustache.

“Nahhh…not yet,” says Mike, “but how many people you got with bids in the betting pool at this point?”

“Twelve.”

“Damn, we’re far too invested in our fellow Freedom Fighters’ love lives.”

“It’s tradition at this point, Mike-y boy. Hell, you should’ve seen the betting pool we had on you and Nanaba. I totally called it though. I thought it would take you about 3 months. Some were betting on much longer.”

Mike’s jaw falls open, “what? You guys had bets on _us_ as well?”

Oruo just laughs.

Meanwhile, Hange and Moblit leave the canteen and make their way back to Hange’s lab. Moblit is unsurprised to find not one, but three virtual whiteboards along the walls covered in Hange’s illegible scrawl. He rolls his eyes, wondering if Hange’s insomnia is medically induced or just a permanent part of their lifestyle.

“Alright, so this is what I’ve figured out. Amongst the many fascinating properties of our runaway’s skin and sub-dermal augmentations, he’s also almost impossible to detect via a normal thermal scan: when I scanned him, I didn’t get anything like the heat sig you’d expect for a human being.”

“How is that good news?”

“Oh, by itself it’s not, only makes the guy _harder_ to find. Pretty terrific tech though, don’t you think?”

Moblit shakes his head, smiling, “You’re not wrong, it is pretty cool. But come on, there’s more isn’t there?”

“Yes! There is. So, I also hypothesize that there must be limits to his invisibility. He probably can’t stay invisible forever, and what happens if he’s wearing clothes or carrying items? Do they disappear too? I doubt it. Any kind of covering would get in the way of his skin’s camouflaging properties. But if he walks around naked, he’ll stick out like a sore thumb if he wants to turn visible again, right? So, let’s assume he finds himself some clothes and decides to _not_ be invisible. Now what? Well, we know that he won’t register on heat scans, but we can see him on visible scans so…”

“ _Gadon Koze!”_ exclaims Moblit in Haitian Creole, “Hange, you’re a genius!”

Hange pauses and a blush colours their cheeks, “Yes. Yes, I am.”

“If we can find him,” continues Moblit, “we can identify him as the only figure who _won’t_ have a heat sig when we overlay the two scans.”

“Exactly! You’re way ahead of me.”

Moblit surprises Hange by wrapping them in a hug and the pair bounce around the room with excitement before going to find Erwin and the others.

* * *

Despite learning more about their invisible runaway, many days pass before there are any new developments in the search. With Armin’s help, Nanaba sets up a smart piece of code to overlay visual and thermal scans from cameras around the city and flag up anyone without a heat signature. At the same time, Hange and Moblit keep looking through the scans, puzzled by the unique alloy which gives the runaway his silver skin.

Erwin and the others are forced to simply wait. It is all they can do. Eventually, the runaway will come out of hiding. Eventually, the runaway will make a mistake and show himself, and when that happens, they will be ready to capture him once more.

Erwin startles awake to the sound of ringing. He’d fallen into a nap slumped at his desk after several nights without enough sleep. Nanaba is calling him. He jumps to his feet.

“Erwin, we have a lead, I think. Got a description in from a food-seller in Kabuki, says a scrawny guy with a silver head tried to steal food from her and she managed to knock him out, has him handcuffed in the back of the restaurant. I think it could be our guy. I can’t get thermal footage though, so I think you and Mike ought to go and check him out.”

“Great. We’ll roll out asap. Send me the details.”

He shrugs into his dark green leather jacket with the signature wings of freedom on the back and rushes out of the room, already calling Mike.

“Mike, did you-“

“Nanaba filled me in. Oruo and Eld are with me. We’ll bring the bikes out front. Meet us there.”

As he races out of the base, he reads the details from Nanaba. The food seller's name is Sasha and Erwin recognises her small restaurant, “The Hot Potato”, as a popular place with the younger street-kids. It’s one of the many establishments under Freedom Fighter protection.

The ride over is short, Erwin riding with Mike so he can draw his pistol readily if needed. He buries his hands in his jacket pockets and fingers the small pin, no bigger than a fly. He hopes he won’t need it.

The smell from the restaurant is mouth-watering as the four Fighters approach, each with the wings of freedom emblazoned on their various jackets, each with weapons raised. Civilians edge away from the area already whispering, wondering what’s about to go down.

A short young man with a buzz-cut stands in the doorway. He stubs out his cigarette as they approach, “Jeez, that was fast,” he says, “we got the thief locked up in the back. He’ll regret trying to steal from us, that’s for sure.”

They edge into the restaurant with caution, making their way through to the back. They find two figures there: the first is a tall black woman with long hair in braids who Erwin recognises as Sasha. She holds a gun trained on the other figure who is struggling against the restraints chaining him to a fridge. He’s wearing an oversized shirt that serves as a dress, but his silver cranium is unmistakable. The struggling stranger goes still when he sees Erwin and the other Fighters enter the room.

Grey eyes meet Erwin’s. For a long moment, nobody moves.

Erwin raises his pistol and keeps it trained on the runaway, “we can take it from here, Sasha, although it seems you’ve done half our work for us.”

“Eh, it’s part of the job. Ain’t got no time for thieves. Make sure this gonk understands how things work around here, ok?” Sasha says firmly before leaving.

Erwin steps forward, pistol pointing directly at the runaway’s head, “remember me? You slit my throat last time we met. Not the politest of introductions.”

The stranger’s expression remains carefully guarded and he doesn’t try and struggle to get free.

“We’ve got you cornered now, alright? So, don’t make a move and we won’t hurt you. But before we take you to base, I’ve just got one question for you: why did you miss?”

Grey eyes widen slightly.

“The whole time you had that knife pressed against my throat, it was right against my carotid artery, perfectly placed to deal a finishing blow. But when you actually made the cut: you missed. I don’t believe it was an accident. I think you missed on purpose. Am I right?”

The stranger looks away, giving Erwin his answer. _Interesting,_ he thinks.

Erwin gestures for Mike to step forward, and the man pulls out a new set of handcuffs. The stranger is sat on the floor, his hands stretched upward where Sasha had haphazardly secured his wrists to the fridge. First, Erwin slips their own handcuffs over the man’s wrists before undoing Sasha’s set and hauling the stranger to his feet by the front of his long shirt.

Their height difference is startling, and Erwin is amazed that this man was able to take him hostage and escape from their base the last time.

There is a split second when the man is on his feet where Erwin pauses, startled by the ferocity in the man’s eyes and he realises too late that the handcuffs have gone on wrong, and his arms are in front of him, not behind.

The next moment, silver arms are looping Erwin forward by the neck and he is drawn down and close as the stranger presses their lips together.

Erwin is completely startled. He freezes.

The stranger takes advantage of his confusion and contorts his bound hands down and around, bending Erwin into an impossible position so that his hands cover Erwin’s and he slips his fingers over Erwin’s hold of the pistol. He whips them both around, and in three short bursts, Mike, Eld, and Oruo all crumple to the floor, but Erwin doesn’t have time to see whether the shots were fatal or not as he grapples with the stranger. He keeps his grip on Erwin’s wrist so that Erwin can’t aim the pistol at him, and he presses himself flush against Erwin, so close that Erwin can’t aim any punches at him either. Through it all the stranger keeps Erwin doubled over, the angle twisting his back impossibly.

He yells and curses as he struggles to get away until finally the stranger steps under and behind him, unwinding his arms from Erwin’s.

It is all Erwin can do to take the pin from his pocket and desperately reach out blindly for the infuriating figure as he steps away, hoping that it somehow sticks. He reaches out to grab the man before he can get away and his hands catch on the fabric of his t-shirt, but he hears it as the cloth rips, the stranger slips under and out of it, and vanishes.

Erwin is left holding the ruined t-shirt.

He swears colourfully, spinning around with his pistol, running out into the main restaurant, eyes watering. Nothing. He runs out into the street, looking desperately around for a silver figure. Nothing.

“Nanaba?” he calls out desperately through his comm, knowing she has been watching the cameras nearby “please tell me you have eyes on him?”

“Erwin! It worked! The pin, it must have stuck, we have him! We have a tracker on our runaway!” Erwin breathes a sigh of relief, “I can see him now, he’s headed towards the river, I’ll pull up visuals. Are you going after him?”

But Erwin’s already moving back into the restaurant, “No, Nanaba, I can’t take him on alone. The others have been shot.”

Nanaba is silent as she processes this, “shot? They’re not…Mike was with you. Please tell me they’re not…”

Erwin reaches the back room once more, hardly daring to breathe. He gasps with relief when he hears Oruo’s voice from the floor, “did you get the bastard?”

“Oh, thank fuck. Mike? Eld?”

“We’re alive,” comes Mike’s voice and Erwin can hear Nanaba swearing her thanks through his comm, “Just…Oh Jesus. Ouch. That fucking bastard shot straight through my knee.”

Erwin bends down beside Mike and sees the shattered metal of his cybernetic right knee, his leg twisted at an odd angle. Eld lies beside him, sweat on his brow and Erwin frowns to see that his right knee has also been shot.

“Nanaba, send the van and Hange. We need a med evac for Mike, Oruo, and Eld. But they’ll live. Nothing Hange can’t patch up.”

“Right on it. Tell Mike he’s an idiot and if he dies on me, I’ll kill him.”

Erwin's lips twitch into a smile as he relays her message.

Oruo groans in pain, and he visibly grits his teeth, “Hey, boss, you didn’t answer my question. Please tell me my shattered patella was worth something.”

“We got him, Oruo. We’ve got a tracker on our invisible runaway,” which is Oruo’s cue to close his eyes in relief.

 _And it only took three shattered knees,_ thinks Erwin. As he sits with the others and waits for the van, he wonders just what they’ve got themselves into.

**Notes for the Chapter:**

> How am I doing? Would people like to see more sexy times? If so, between who? 
> 
> What antics shall take place next between Levi and Erwin? So far Levi's tried to kill him, and then kissed him, what shall their next encounter be like...


End file.
